The ancient Greeks have never formed a common state in which all could join together. Their favorite form of government was the polis (city-state). The emergence of poleis were influenced mainly by the following circumstances: the development of trade and commerce, the separation of crafts from the peasant economy, disintegration of clan-based communities, the class genesis and contradiction between the ruling class and the masses.
The character, size and the importance of poleis was affected by geographical location, economic conditions, the composition of the citizens and many other circumstances. Each poleis had its own peculiarities, each of them lived out his historical life.
Classical Greek polis was the economic and socio-political community on a larger or smaller area, with one major military, cult and administrative center. Many poleis Greeks founded by Synoecism- consensual joining several neighboring villages into the substructure of the polis.
Sparta had spread the most with the Messenia had very large estate for the Greek polis. Other major poleis were Syracuse, Athens throughout Attica, Thebes and Corinth. Many islands were a private poleis (Del, Aegina, Sam …), while on the larger islands (Crete, Euboea) were more cities.
Greek seaside poleis in which were more developed crafts, trade and monetary economy improved rapidly their social life. Economic and social rise was first noticed in cities in Asia Minor, in the Ionian part:
The first risen up was Miletus, polis with a large and wide agricultural area, main craft and trade center. Miletus has culturally early risen up and from 8th to 6th century. BC was one of the most important Greek cities. Its sailors were establishing commercial bases all over the Mediterranean.
With Miletus, Ephesus developed too , thriving city, which was supported by close ties with neighbours.
Greek cities in Asia Minor Aeolid have lagged behind those of Ionia. Mytilene was noted on the Lesbos island as a metropolis of many settlements.
Among the Greek poleis in the Balkan, an early economic and cultural progress had Corinth, Aegina and Euboean Chalkida, and before all Argos was the closest successor of Mycenae. By the 5th century BC all of them were reached and surpassed by Athens.
Corinth had been since the 8th century. BC important economic center. It had a port on both sides of the coast (Isthmos) where the merchant ships sailed on all side. Corinthians were more interested in the Balkans and the western coast of Sicily, where they founded colonies. The biggest was Corcyra on the island of Corcyra and Syracuse in Sicily. Apparently, they were the best Greek shipbuilders. Their Trireme was the classical prototype of Greek warships.